Lately I've been getting CAPTCHAs almost every time I post an answer. Is there any particular behavior that makes SO trigger the bot test so often?

EDIT: It just occurred to me that most of these CATPCHAs have been occurring just after experiencing missing previews due to this Chrome 11 issue. I guess downloading a page, but not the JavaScript might be considered bot-like behavior, so these issues might be connected. Can anyone confirm this?